The development of wireless communication technologies enables data transmission/reception and data sharing between different electronic devices. For example, it is possible to directly transmit a multimedia file, which includes an image file stored in, for example, a digital camera or a multimedia reproducer, to a smart phone or a notebook computer. A data transmission technology between electronic devices may also be usefully used in a medical field. For example, information about a patient, which is obtained from a medical electronic device (e.g., an ElectroCardioGraphy (ECG) sensor to be attached to a human body) may be transmitted to, for example, a Personal Computer (PC) or a mobile communication terminal. Such inter-device information transmission may be performed through a communication method (e.g., wireless LAN, Bluetooth, or Near Field Communication (NFC)).
Meanwhile, power transmission/reception, as well as ordinary communication, has also recently been implemented in a wireless manner, rather than a wired manner. In order to transmit/receive power in a wireless manner, a device that receives power (e.g., an electronic device such as a mobile communication terminal) is provided with a secondary coil or a resonance circuit. The secondary coil or the resonance circuit equipped in an electronic device receives power from a primary coil or a resonance circuit equipped in a power transmission device (e.g., a wireless charger), in an electromagnetic induction manner or a resonance manner.